This invention relates to a process for trapping particulate matter in gas streams exiting combustion equipment, particularly gas streams which further pass through a catalytic system. This invention also relates to a trap for use in such a process.
Current technology for removal of oxides of nitrogen (NOx), organic compounds, carbon monoxide, dioxins and other environmentally undesirable pollutants, including combinations thereof, from high temperature gas streams ( greater than 150xc2x0 C.) many times makes use of catalyst wherein the gas stream is passed over relatively small diameter catalyst pellets. The catalyst pores and void spaces between catalyst particles can become fouled with particulate matter carried in the gas stream. As the catalyst pores and void spaces fill with particulate matter, a pressure drop occurs and eventually this pressure drop becomes excessive, such that the process equipment moving the gas through the system cannot maintain the required flow rate. When this occurs, the flow must be stopped so the catalyst can be cleaned or replaced.
In very severe cases particulate clogging may result in a time in service for a catalyst system which is less than the typical time between maintenance shutdowns for the combustion equipment associated with it. Such an interruption produces a considerable impact on the overall combustion equipment reliability and time on line.
The typical sources of particulate matter are rust, dust soot, insulation fibers or particles, and metal flake from the combustion equipment. It is therefore an object of the invention to remove particulate matter upstream of the catalyst. This in turn will allow the combustion equipment producing or handling hot gas streams to remain in service between scheduled shutdowns.
There is provided a process for trapping particulate matter in a gas stream exiting combustion equipment, said process comprising:
providing a combustion equipment with one or more exits for exhaust gases, each said one or more exits connected to one or more ducts; and
placing at least one particulate trap in at least one of said one or more ducts;
wherein said at least one particulate trap is removable and/or replaceable while said combustion equipment is online.
There is further provided a process for trapping particulate matter from a gas stream exiting combustion equipment, said process comprising:
providing a combustion equipment with one or more exits for exhaust gases, each said one or more exits connected to one or more ducts; and
placing at least one particulate trap in at least one of said one or more ducts;
wherein said at least one particulate trap is cleanable while said combustion equipment is online.
There is also provided a particulate trap for removing particulate matter from a gas stream, said particulate trap comprising:
a plurality of filtering layers, each layer having a mesh or pore size; and
a housing to contain said layers in a predetermined shape.